1 /* SPDX-License-Identifier: GPL-2.0-only */ 2 /* 3 * Copyright (C) 2012 Regents of the University of California 4 */ 5 6 #ifndef _ASM_RISCV_PROCESSOR_H 7 #define _ASM_RISCV_PROCESSOR_H 8 9 #include <linux/const.h> 10 #include <linux/cache.h> 11 #include <linux/prctl.h> 12 13 #include <vdso/processor.h> 14 15 #include <asm/ptrace.h> 16 17 /* 18 * addr is a hint to the maximum userspace address that mmap should provide, so 19 * this macro needs to return the largest address space available so that 20 * mmap_end < addr, being mmap_end the top of that address space. 21 * See Documentation/arch/riscv/vm-layout.rst for more details. 22 */ 23 #define arch_get_mmap_end(addr, len, flags) \ 24 ({ \ 25 unsigned long mmap_end; \ 26 typeof(addr) _addr = (addr); \ 27 if ((_addr) == 0 || is_compat_task() || \ 28 ((_addr + len) > BIT(VA_BITS - 1))) \ 29 mmap_end = STACK_TOP_MAX; \ 30 else \ 31 mmap_end = (_addr + len); \ 32 mmap_end; \ 33 }) 34 35 #define arch_get_mmap_base(addr, base) \ 36 ({ \ 37 unsigned long mmap_base; \ 38 typeof(addr) _addr = (addr); \ 39 typeof(base) _base = (base); \ 40 unsigned long rnd_gap = DEFAULT_MAP_WINDOW - (_base); \ 41 if ((_addr) == 0 || is_compat_task() || \ 42 ((_addr + len) > BIT(VA_BITS - 1))) \ 43 mmap_base = (_base); \ 44 else \ 45 mmap_base = (_addr + len) - rnd_gap; \ 46 mmap_base; \ 47 }) 48 49 #ifdef CONFIG_64BIT 50 #define DEFAULT_MAP_WINDOW (UL(1) << (MMAP_VA_BITS - 1)) 51 #define STACK_TOP_MAX TASK_SIZE_64 52 #else 53 #define DEFAULT_MAP_WINDOW TASK_SIZE 54 #define STACK_TOP_MAX TASK_SIZE 55 #endif 56 #define STACK_ALIGN 16 57 58 #define STACK_TOP DEFAULT_MAP_WINDOW 59 60 /* 61 * This decides where the kernel will search for a free chunk of vm 62 * space during mmap's. 63 */ 64 #ifdef CONFIG_64BIT 65 #define TASK_UNMAPPED_BASE PAGE_ALIGN((UL(1) << MMAP_MIN_VA_BITS) / 3) 66 #else 67 #define TASK_UNMAPPED_BASE PAGE_ALIGN(TASK_SIZE / 3) 68 #endif 69 70 #ifndef __ASSEMBLY__ 71 72 struct task_struct; 73 struct pt_regs; 74 75 /* 76 * We use a flag to track in-kernel Vector context. Currently the flag has the 77 * following meaning: 78 * 79 * - bit 0: indicates whether the in-kernel Vector context is active. The 80 * activation of this state disables the preemption. On a non-RT kernel, it 81 * also disable bh. 82 * - bits 8: is used for tracking preemptible kernel-mode Vector, when 83 * RISCV_ISA_V_PREEMPTIVE is enabled. Calling kernel_vector_begin() does not 84 * disable the preemption if the thread's kernel_vstate.datap is allocated. 85 * Instead, the kernel set this bit field. Then the trap entry/exit code 86 * knows if we are entering/exiting the context that owns preempt_v. 87 * - 0: the task is not using preempt_v 88 * - 1: the task is actively using preempt_v. But whether does the task own 89 * the preempt_v context is decided by bits in RISCV_V_CTX_DEPTH_MASK. 90 * - bit 16-23 are RISCV_V_CTX_DEPTH_MASK, used by context tracking routine 91 * when preempt_v starts: 92 * - 0: the task is actively using, and own preempt_v context. 93 * - non-zero: the task was using preempt_v, but then took a trap within. 94 * Thus, the task does not own preempt_v. Any use of Vector will have to 95 * save preempt_v, if dirty, and fallback to non-preemptible kernel-mode 96 * Vector. 97 * - bit 30: The in-kernel preempt_v context is saved, and requries to be 98 * restored when returning to the context that owns the preempt_v. 99 * - bit 31: The in-kernel preempt_v context is dirty, as signaled by the 100 * trap entry code. Any context switches out-of current task need to save 101 * it to the task's in-kernel V context. Also, any traps nesting on-top-of 102 * preempt_v requesting to use V needs a save. 103 */ 104 #define RISCV_V_CTX_DEPTH_MASK 0x00ff0000 105 106 #define RISCV_V_CTX_UNIT_DEPTH 0x00010000 107 #define RISCV_KERNEL_MODE_V 0x00000001 108 #define RISCV_PREEMPT_V 0x00000100 109 #define RISCV_PREEMPT_V_DIRTY 0x80000000 110 #define RISCV_PREEMPT_V_NEED_RESTORE 0x40000000 111 112 /* CPU-specific state of a task */ 113 struct thread_struct { 114 /* Callee-saved registers */ 115 unsigned long ra; 116 unsigned long sp; /* Kernel mode stack */ 117 unsigned long s[12]; /* s[0]: frame pointer */ 118 struct __riscv_d_ext_state fstate; 119 unsigned long bad_cause; 120 u32 riscv_v_flags; 121 u32 vstate_ctrl; 122 struct __riscv_v_ext_state vstate; 123 unsigned long align_ctl; 124 struct __riscv_v_ext_state kernel_vstate; 125 }; 126 127 /* Whitelist the fstate from the task_struct for hardened usercopy */ 128 static inline void arch_thread_struct_whitelist(unsigned long *offset, 129 unsigned long *size) 130 { 131 *offset = offsetof(struct thread_struct, fstate); 132 *size = sizeof_field(struct thread_struct, fstate); 133 } 134 135 #define INIT_THREAD { \ 136 .sp = sizeof(init_stack) + (long)&init_stack, \ 137 .align_ctl = PR_UNALIGN_NOPRINT, \ 138 } 139 140 #define task_pt_regs(tsk) \ 141 ((struct pt_regs *)(task_stack_page(tsk) + THREAD_SIZE \ 142 - ALIGN(sizeof(struct pt_regs), STACK_ALIGN))) 143 144 #define KSTK_EIP(tsk) (task_pt_regs(tsk)->epc) 145 #define KSTK_ESP(tsk) (task_pt_regs(tsk)->sp) 146 147 148 /* Do necessary setup to start up a newly executed thread. */ 149 extern void start_thread(struct pt_regs *regs, 150 unsigned long pc, unsigned long sp); 151 152 extern unsigned long __get_wchan(struct task_struct *p); 153 154 155 static inline void wait_for_interrupt(void) 156 { 157 __asm__ __volatile__ ("wfi"); 158 } 159 160 extern phys_addr_t dma32_phys_limit; 161 162 struct device_node; 163 int riscv_of_processor_hartid(struct device_node *node, unsigned long *hartid); 164 int riscv_early_of_processor_hartid(struct device_node *node, unsigned long *hartid); 165 int riscv_of_parent_hartid(struct device_node *node, unsigned long *hartid); 166 167 extern void riscv_fill_hwcap(void); 168 extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src); 169 170 extern unsigned long signal_minsigstksz __ro_after_init; 171 172 #ifdef CONFIG_RISCV_ISA_V 173 /* Userspace interface for PR_RISCV_V_{SET,GET}_VS prctl()s: */ 174 #define RISCV_V_SET_CONTROL(arg) riscv_v_vstate_ctrl_set_current(arg) 175 #define RISCV_V_GET_CONTROL() riscv_v_vstate_ctrl_get_current() 176 extern long riscv_v_vstate_ctrl_set_current(unsigned long arg); 177 extern long riscv_v_vstate_ctrl_get_current(void); 178 #endif /* CONFIG_RISCV_ISA_V */ 179 180 extern int get_unalign_ctl(struct task_struct *tsk, unsigned long addr); 181 extern int set_unalign_ctl(struct task_struct *tsk, unsigned int val); 182 183 #define GET_UNALIGN_CTL(tsk, addr) get_unalign_ctl((tsk), (addr)) 184 #define SET_UNALIGN_CTL(tsk, val) set_unalign_ctl((tsk), (val)) 185 186 #endif /* __ASSEMBLY__ */ 187 188 #endif /* _ASM_RISCV_PROCESSOR_H */ 189